This invention relates to a rain gutter and in particular to an enclosed rain gutter that collects water and rejects debris. The rain gutter of the present invention collects rain water flowing from a roof structure and conducts it to a downspout. The invention rain gutter includes a channel that is covered by a collecting surface. The collecting surface has openings that divert water into the channel by using the property of water that causes it to adhere to a surface. While the collecting surface openings divert water into the channel, they also exclude debris from entering the channel and in particular they exclude debris that would be large enough to obstruct a downspout.
Any home owner whose home is located near vegetation knows the frustration of obstructed rain gutters. Removing debris from rain gutters is a time consuming, difficult and often dangerous task. The prior art describes numerous attempts to provide a rain gutter that will not collect debris and become obstructed. Various types of screens and coverings have been marketed for preventing leaves from collecting in rain gutters. Many of these screens or meshes, when placed over conventional rain gutters only serve to provide another even more unsightly means for trapping and collecting aebris such as leaves and twigs.
Common prior art rain gutters become obstructed because they are open to falling debris and because the flow of water down the length of the gutter is not managed or controlled. Common prior art rain gutters of the type having a generally flat bottomed, constant and open cross section are an obvious but flawed solution to a problem that seems deceptively simple. A rain gutter need only to perform two functions: 1. collect rain water, and, 2. convey collected rain water to a downspout. A prior art rain gutter is generally flat and open at the top and has an area for collecting water that is many times greater than the actual area of any stream of water that could exit the gutter via a downspout. A prior art rain gutter would overflow long before the cross sectional area of the flow of water into the gutter reached even a small fraction of the total collecting area available. While the vastly oversized, open collecting area of a prior art rain gutter can collect water flowing off of a roof, it is even more effective as a collector of dead leaves and other debris. Most debris falls into the prior art gutter during dry conditions and then is trapped in place during a rain storm when the debris obstructs a downspout. Once a prior art gutter is obstructed, it collects water, overflows and allows adjacent building structures to be water damaged. Prior art rain gutters can also collect snow that after thaw and freeze cycles can accumulate as ice. Moreover, sheets of Ice that form on a sloped roof can slide down into a prior art rain gutter and damage or destroy the gutter.
An objective of the present invention is to provide a rain gutter that will collect rain water while not collecting any debris that could obstruct water from entering the gutter or obstruct a downspout so that water can not flow out of the gutter. Another objective of the present invention is to provide a rain gutter that is not open to falling debris or snow. Yet another objective of the present invention is to provide a rain gutter that is not open to sheets of ice or other objects that my slide down a roof. Still another objective of the present invention is to provide a rain gutter having a channel that will carry a large flow of water at a relatively constant velocity along its length over a wide range of drainage load conditions so that any small debris that enters the channel is washed away as water is conveyed to a downspout.
The invention rain gutter is designed to be mounted at the lower edge of a sloped, roof of a building adjacent to a vertical surface under the lower edge of the roof. The rain gutter can be fashioned from a continuous sheet of metal. It includes a channel for conveying water to a downspout and a collecting flange for collecting water and diverting it into the channel. Preferably, the channel has a circular cross section that is large enough and extensive enough to carry a substantial flow of water to a downspout. The inside wall of the channel can be mounted to a vertical surface under the edge of the roof or to an eaves under the roof. The collecting flange extends from the outside wall of the channel and over the channel. Preferably, the collecting flange is integral with the outside wall of the channel. The collecting flange can completely cover the channel and can even extend past the inside wall of the channel. The collecting flange can be inserted under the bottom edge of any material covering the roof. Yet, the collecting flange could also be envisioned as a separate cover that can be added to an existing rain gutter.
As rain water flows down from the roof, it encounters the collecting flange and begins to flow as a thin sheet that adheres to the collecting flange surface. The collecting flange has a generally hydrophilic surface and has a pattern of openings that conduct the flow of water into the channel. These openings are sized and arranged to exploit the physical properties of flowing water so that the water is conducted into the channel while all but the smallest debris is not conducted into the channel. One possible pattern of openings includes a pattern of openings having diagonal edges situated above a pattern of collecting slots that are located under gaps between the lower ends of the openings having diagonal edges. The openings having diagonal edges have upper edges that are preferably oriented at an angle of not substantially more than 45xc2x0 with respect to the direction of the flow of water. When the film of flowing water encounters the diagonal edges, it divides and follows each of the upper edges without flowing into the openings. The water flowing along each diagonal edge of each opening forms into a small, fast moving stream. The collecting slots situated under the gaps between the lower ends of the openings include inwardly turned collecting tabs that divert the small streams of water into the gutter channel. The openings having diagonal edges described above may also be replaced by zones on the surface the collecting flange that are non-hydrophilic, that is zones that have a surface that repels water. Another arrangement of openings does not include collecting slots. With this arrangement, diagonal openings have upper edge that change direction so that the upper edge of the diagonal opening defines a xe2x80x9cVxe2x80x9d shaped angle at the lower end of the diagonal opening. With this second alternative arrangement, a small, fast moving stream of water is unable to adhere to the collecting flange surface where the upper edge changes direction and will therefore separate from the surface of the collecting flange and discharge down through the lower end of the diagonal opening into the rain gutter channel. Yet another example arrangement of openings includes a series of overlapping obtuse triangles having inwardly bent triangular collecting tabs. Because the lower edge of an inwardly bent collecting tab of this arrangement is slightly angled in relation to the descending contour of the surface, a transverse flow is set up on the inwardly bent tab so that water flowing around an adjacent opening is induced into flowing onto the tab and into the channel. A flowing sheet of water will move along an edge even if that edge is oriented at only a slight angle that is not normal with respect to the contour and the direction of the flow of water.
In addition to the alternative arrangements of openings and non-hydrophilic zones as described above, the collecting flange itself can be alternately further formed to define a small radius folded edge so that it has an upper portion which is secured to the roof of the building and might be called a mounting flange and a lower portion which performs the water collecting function would still be called a collecting flange. With this alternate configuration, the upper portion or mounting flange extends parallel with the slope of the roof, while the lower portion or collecting flange curves inwardly toward the building and then outwardly away from the building toward the outside wall of the channel. Between the upper portion or mounting flange and the lower, collecting flange is a folded edge that has a radius substantially less than one half inch and that preferably has a radius of about 0.10 inch. The various openings and non-hydrophilic zones described above can be positioned in the lower, inwardly curved collecting flange and are positioned so that the portions of the openings where water is collected into the channel are located on the portion of the curved collecting flange that is sloping back toward the outside wall of the channel. With this configuration, a sheet of flowing water accelerates around the curved collecting flange and pulls the flowing sheet of water around the small radius folded edge while any debris is unable to follow the torturous path around the folded edge and is ejected from the system.
With any of the above described arrangements, it is important that any portion of the gutter where water is being diverted into the channel have a surface that is generally hydrophilic. Highly water repellent surfaces would be unsuitable because a flowing sheet of water would separate from such a surface. The inventor has found that thin gauge aluminum having a non-glossy PVC coating provides a suitable surface for the mounting flanges and collecting flanges described above. However, any similarly hydrophilic surface would be suitable for these applications.
With the above described arrangements, dead leaves and other debris do not follow the surface tension induced flow of the water and are pushed over the edge of mounting flange or collecting flange. When the portion of the collecting flange having diagonal openings or collecting slots is inwardly curved, then even small articles of air born materials can not settle into the openings. If the rain gutter channel has a circular cross section, if the circular cross section of the channel is properly adjusted and if the channel is properly sloped toward a downspout, the velocity of flow in the channel, at various volume flow rates would be substantially constant so that even very small debris that might enter the channel would be washed out even at low volume flow rates. A channel having a circular shape has the added advantage of not covering a surface to which it is mounted. A flat sided channel will lay flat against an eaves surface to which it is mounted and allow moisture to attack that surface. A circular channel will allow air to circulate between the channel any surface to which it is mounted.
Accordingly, the rain gutter of the present invention provides a way to collect rain water from a roof structure without collecting debris that can obstruct the gutter system. The invention rain gutter does not collect debris that can obstruct downspouts. Because even the small amount of small debris that enters an invention rain gutter is washed out even at relatively low volume flow rates, the accumulation of debris that plagues prior art rain gutters does not occur. The invention rain gutter collects rain water while rejecting virtually all debris and therefore can function at an optimum level of performance for a very long period of time without any need for maintenance or cleaning.